CC1705

CASEstudy
"The HoleBASE SI Extension for Civil 3D streamlined the flow of information from
our site investigation and testing to drawing production and visualisation. As a
result, we had more time to refine our design and were more responsive to
changes from new geotechnical data."
Jerome Chamfray BIM Manager Atkins
model-based, multidisciplinary Civil 3D
environment.
"With the HoleBASE SI Extension for
Civil 3D, we could quickly combine,
organise, and manage geology data,
and then see that data in the context of
existing and proposed above and
below-ground structures," says Jerome
Chamfray, an Atkins BIM Manager. "This
helped us visually understand and
evaluate the design alignment, pinpoint
potential construction obstructions, and
determine what new site investigations
were needed." Moreover, Atkins used
Civil 3D to automatically generate
earthworks quantities for project costing
and risk assessment.
GEOLOGICAL MODELLING
Atkins planned its ground investigation
by importing historical data (from
previous Atkins projects in the same
area and British Geological Survey
data) into HoleBASE SI to determine
requirements for new borehole data.
"By reusing this historical data in
HoleBASE SI, we significantly reduced
the amount of exploratory holes that
were required on-site, which translated
into reduced project time and cost for
our client," says Miles. After completing
the on-site ground investigation, the
data was merged with the historical
information in HoleBASE SI for
engineering interpretation and stratum
identification.
In parallel, the firm used Civil 3D to
create an existing conditions model of
the project area (both above and below
the surface) based on a variety of data
sources such as TfL's as-built data for
the cable car foundations, and
historical data for the demolished
gasworks foundations, warehouses, and
piers and foundations of the old dock
entrance. Next, Atkins added the
proposed tunnel alignment and other
proposed structures relating to the tunnel.
The firm then used the HoleBASE SI
Extension for Civil 3D to automatically
layer the geotechnical data into the
Civil 3D model. This enabled Atkins
engineers to visualise the geotechnical
data in relation to the existing site and
proposed design. "Having a live link
between the HoleBASE SI database
and Civil 3D dramatically improved our
design process," says Chamfray.
"Whenever the HoleBASE SI database
was updated, those changes were
automatically reflected in the Civil 3D
model and we didn't have to waste time
recreating or manually synchronising
the geotechnical data in Civil 3D, which
gave us more time to refine and
improve our design."
EXCAVATION AND EXTRACTION
ISSUES
Atkins also used Civil 3D to extract
volumes for the different materials that
will be excavated. "We were able to
identify areas that will require specific
treatment on-site during excavations,
such as the treatment of hazardous
material for example," says Miles. "This
gave us a clearer picture as to what
material could be reused for
construction and helped us refine our
cost estimate."
Production of geological sections and
other inter-disciplinary checks were
also facilitated by having all the
information in a common data
environment. "The Civil 3D model
helped us maximise efficiency and
increase our level of design
confidence," says Miles. "This 3D
design environment allowed us to
visualise the subsurface conditions in a
new way - giving us a better
understanding of the site for more
informed decision making."
For example, the original design for
the road as it entered one of the portals
placed the road's ground slab below the
local water table level, which would
have led to a continuous flow of ground
water into the tunnel. "With the ground
slab and the geological model in the
same 3D environment, we could easily
see and quickly make the necessary
design changes," says Miles. Atkins
also used the Civil 3D project model in
Autodesk Navisworks for client and
partner design reviews and
walkthroughs, and in Autodesk 3ds Max
to create high-end project renderings
for TfL's public outreach efforts.
THE RESULT
"The HoleBASE SI Extension for Civil
3D streamlined the flow of information
from our site investigation and testing
to drawing production and
visualisation," says Chamfray. "As a
result, we had more time to refine our
design and were more responsive to
changes from new geotechnical data."
"The use of a fully integrated,
multidisciplinary Civil 3D model,
including subsurface geology, has
been a real eye-opener for the team,"
says Miles. "By visualising ground
conditions in a design context, we can
reduce project risk and project costs
during construction."
www.autodesk.com/civil3D
www.keynetix.com/holebase/civil3d
May/June 2017 29